"Invalid License Specified" attempting to use Team Calendars trial

I just signed up for a trial of Team Calendars on my JIRA+Confluence hosted subscription. When loading the Add On management page, I got an error that indicated that I should look in the logs. When I access Team Calendars, there is a red bar across the top of the screen that says "Invalid license specified." I don't see a way to create or subscribe to a calendar, and presume that this is because of the license issue.